Agricultural implements such as potato planters utilize vertical belt systems with cups for the metering of seed. The cups are attached to an endless belt in two or more columns with the cups staggered vertically from one column to the next. The belt includes a portion which moves upwardly through the hopper from a lower seed puddle to an uppermost pulley, and thereafter a downward portion inverts the cups as they move towards the ground. The cups open upwardly into the seed puddle and then open downwardly to release the seeds towards a furrow in the ground on the downward portion. Adjacent cups are adapted to receive seed as the cups moves upwardly with the belt through the hopper. The seeds typically are singulated by a vibrating device or other singulating structure during upward movement of the cups so that only an individual seed remains in each cup.
Vertical belt cup size is chosen to match seed size. Seed size within a batch of seed can vary, and the seeds can overlap in the cups. Occasionally more than one seed per cup is elevated, and during singulation a seed can return to the puddle and dislodge seeds from adjoining cups. As speed of a vertical belt planter increases, population control typically deteriorates.
Hopper floors are angled downwardly to form the seed puddle toward the lower portion of the vertical belt. Seed piled within the hopper applies considerable pressure in the pickup area resulting in seed damage and increased churning as the cups pass through the seed puddle. The percentage of cup fill and amount of seed damage is influenced by the amount of seed in the hopper.
Typical cups in vertical belt meters are intended for use with round or oval seeds, such as potatoes. Cylindrical seeds, such as short sugar cane billets, are poorly matched to the cup shape. Unacceptable cup fill variations occur for cylindrically shaped seeds. As the cup transitions from an upwardly directed pickup and singulating orientation on the upward portion of the belt path to a downwardly directed release position on the downward portion of the belt path, the seed exits its pickup cup and lodges against the opposite side of the lower adjacent cup with negligible indexing or orientation control for the released seed. For round and oval seeds such as potatoes, the lack of such indexing or orientation usually is not a problem. However, for other seeds such as cylindrical sugar cane seeds, seed position in the furrow is more critical and lack of indexing or orientation control results in decreased productivity.